1 /* 2 * Copyright © 2016 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 #ifndef __I915_UTILS_H 26 #define __I915_UTILS_H 27 28 #undef WARN_ON 29 /* Many gcc seem to no see through this and fall over :( */ 30 #if 0 31 #define WARN_ON(x) ({ \ 32 bool __i915_warn_cond = (x); \ 33 if (__builtin_constant_p(__i915_warn_cond)) \ 34 BUILD_BUG_ON(__i915_warn_cond); \ 35 WARN(__i915_warn_cond, "WARN_ON(" #x ")"); }) 36 #else 37 #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")") 38 #endif 39 40 #undef WARN_ON_ONCE 41 #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")") 42 43 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \ 44 __stringify(x), (long)(x)) 45 46 #if defined(GCC_VERSION) && GCC_VERSION >= 70000 47 #define add_overflows_t(T, A, B) \ 48 __builtin_add_overflow_p((A), (B), (T)0) 49 #else 50 #define add_overflows_t(T, A, B) ({ \ 51 typeof(A) a = (A); \ 52 typeof(B) b = (B); \ 53 (T)(a + b) < a; \ 54 }) 55 #endif 56 57 #define add_overflows(A, B) \ 58 add_overflows_t(typeof((A) + (B)), (A), (B)) 59 60 #define range_overflows(start, size, max) ({ \ 61 typeof(start) start__ = (start); \ 62 typeof(size) size__ = (size); \ 63 typeof(max) max__ = (max); \ 64 (void)(&start__ == &size__); \ 65 (void)(&start__ == &max__); \ 66 start__ > max__ || size__ > max__ - start__; \ 67 }) 68 69 #define range_overflows_t(type, start, size, max) \ 70 range_overflows((type)(start), (type)(size), (type)(max)) 71 72 /* Note we don't consider signbits :| */ 73 #define overflows_type(x, T) \ 74 (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) 75 76 #define ptr_mask_bits(ptr, n) ({ \ 77 unsigned long __v = (unsigned long)(ptr); \ 78 (typeof(ptr))(__v & -BIT(n)); \ 79 }) 80 81 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1)) 82 83 #define ptr_unpack_bits(ptr, bits, n) ({ \ 84 unsigned long __v = (unsigned long)(ptr); \ 85 *(bits) = __v & (BIT(n) - 1); \ 86 (typeof(ptr))(__v & -BIT(n)); \ 87 }) 88 89 #define ptr_pack_bits(ptr, bits, n) ({ \ 90 unsigned long __bits = (bits); \ 91 GEM_BUG_ON(__bits & -BIT(n)); \ 92 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \ 93 }) 94 95 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT) 96 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT) 97 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT) 98 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT) 99 100 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member) 101 102 #define fetch_and_zero(ptr) ({ \ 103 typeof(*ptr) __T = *(ptr); \ 104 *(ptr) = (typeof(*ptr))0; \ 105 __T; \ 106 }) 107 108 /* 109 * container_of_user: Extract the superclass from a pointer to a member. 110 * 111 * Exactly like container_of() with the exception that it plays nicely 112 * with sparse for __user @ptr. 113 */ 114 #define container_of_user(ptr, type, member) ({ \ 115 void __user *__mptr = (void __user *)(ptr); \ 116 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 117 !__same_type(*(ptr), void), \ 118 "pointer type mismatch in container_of()"); \ 119 ((type __user *)(__mptr - offsetof(type, member))); }) 120 121 /* 122 * check_user_mbz: Check that a user value exists and is zero 123 * 124 * Frequently in our uABI we reserve space for future extensions, and 125 * two ensure that userspace is prepared we enforce that space must 126 * be zero. (Then any future extension can safely assume a default value 127 * of 0.) 128 * 129 * check_user_mbz() combines checking that the user pointer is accessible 130 * and that the contained value is zero. 131 * 132 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success. 133 */ 134 #define check_user_mbz(U) ({ \ 135 typeof(*(U)) mbz__; \ 136 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \ 137 }) 138 139 static inline u64 ptr_to_u64(const void *ptr) 140 { 141 return (uintptr_t)ptr; 142 } 143 144 #define u64_to_ptr(T, x) ({ \ 145 typecheck(u64, x); \ 146 (T *)(uintptr_t)(x); \ 147 }) 148 149 #define __mask_next_bit(mask) ({ \ 150 int __idx = ffs(mask) - 1; \ 151 mask &= ~BIT(__idx); \ 152 __idx; \ 153 }) 154 155 #include <linux/list.h> 156 157 static inline void __list_del_many(struct list_head *head, 158 struct list_head *first) 159 { 160 first->prev = head; 161 WRITE_ONCE(head->next, first); 162 } 163 164 /* 165 * Wait until the work is finally complete, even if it tries to postpone 166 * by requeueing itself. Note, that if the worker never cancels itself, 167 * we will spin forever. 168 */ 169 static inline void drain_delayed_work(struct delayed_work *dw) 170 { 171 do { 172 while (flush_delayed_work(dw)) 173 ; 174 } while (delayed_work_pending(dw)); 175 } 176 177 static inline const char *yesno(bool v) 178 { 179 return v ? "yes" : "no"; 180 } 181 182 static inline const char *onoff(bool v) 183 { 184 return v ? "on" : "off"; 185 } 186 187 static inline const char *enableddisabled(bool v) 188 { 189 return v ? "enabled" : "disabled"; 190 } 191 192 #endif /* !__I915_UTILS_H */ 193